The Research Of High-speed Data Processing Technology Of PEM Interference Signal Based On SOPC

The photo-elastic modulative spectrometer has the characteristics of high speed,high sensitivity,high shock resistance and wide spectrum.It has wide application prospect in the construction of national defense,environmental monitoring and the exploration of the universe.As the modulation device of the photo-elastic modulative spectrometer,the photo-elastic modulator has the highly modulated frequency and the nonlinearly modulated optical path difference.However,the modulated interference signal is not consistent with the actual spectral characteristics due to the limitations of light source,the ADC sampling rate and the inaccurate capture of the zero-path difference.Therefore,it is necessary to study the data processing technology of the whole interference signal,such as apodization,phase error correction and non-uniform fast Fourier transform(NUFFT)algorithm.The thesis based on the analysis of photo-elastic modulator Fourier transform tech nique,non-uniform interference signal processing and high-speed data processing techn ology,research the high-speed data processing technology of on-a-programmable-chip(SOPC)including apodization,phase error correction,NUFFT algorithm.For the photo-elastic modulation interference signal zero optical path and phase distort phenomenon,Mertz method is used to realize the phase error correction of the interference signal after hanning window apodization.The method has low complexity and can accurately realize the phase error correction of the interference signal.For the characteristics of interference signal phase nonlinear under the nonlinear driver,the NUFFT algorithm of Gaussian kernel function interpolation is studied.The algorithm can accurately realize the photo-elastic modulation interference signal spectrum reconstruction based on the fixed parameters.A photo-elastic modulation interference signal processing system is b uilt by using Xilinx Spartan6 series XC6SLC150T-3FGG676 C chip and embedded Mic ro Blaze.The system can achieve the functions including apodization,Mertz method p hase error correction,NUFFT algorithm of interference signal,and so on.The photo-elastic modulation interference signal testing platform is built to implement apodization,phase error correction,and NUFFT algorithm of the modulated interference signal for polychromatic light source.The experimental results show that the system not onlycan realize the high-speed data processing with the maximum optical path difference of 69.6?m modulation interference signal,but also has a higher integration performance.